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| Registros recuperados: 28 | |
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| Hernvann, Pierre-yves; Gascuel, Didier; Grüss, Arnaud; Druon, Jean-noël; Kopp, Dorothee; Perez, Ilan; Piroddi, Chiara; Robert, Marianne. |
| Both trophic structure and biomass flow within marine food webs are influenced by the abiotic environment and anthropogenic stressors such as fishing. The abiotic environment has a large effect on species spatial distribution patterns and productivity and, consequently, spatial co-occurrence between predators and prey, while fishing alters species abundances and food-web structure. In order to disentangle the impacts of the abiotic environment and fishing in the Celtic Sea ecosystem, we developed a spatio-temporal trophic model, specifically an Ecopath with Ecosim with Ecospace model, for the period 1985–2016. In this model, particular attention was paid to the parameterization of the responses of all trophic levels to abiotic environmental changes.... |
| Tipo: Text |
Palavras-chave: Celtic Sea; Ecosystem modeling; Habitat model; Environment; Ecopath with Ecosim and Ecospace; Primary production; Fishing impact. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00662/77419/79084.pdf |
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| Nicolaus, E. E. Manuel; Barry, Jon; Bolam, Thi P. C.; Lorance, Pascal; Marandel, Florianne; Phillips, Sophy R. Mccully; Neville, Suzanna; Ellis, Jim R.. |
| Trace metal concentrations in muscle and liver tissues from two offshore species of skate were examined. Concentrations of mercury in muscle of Leucoraja circularis (n = 20; 23–110.5 cm total length, 157–490 m water depth) and L. fullonica (n = 24; 28.5–100 cm total length, 130–426 m water depth) were 0.02–1.8 and 0.04–0.61 mg kg− 1, respectively. Concentrations of both As and Hg increased with total length. Only the largest specimen had a concentration of Hg in muscle > 1.0 mg kg− 1. Data were limited for specimens > 90 cm long, and further studies on contaminants in larger-bodied skates could usefully be undertaken. |
| Tipo: Text |
Palavras-chave: Trace metals; Sandy ray; Shagreen ray; Bay of Biscay; Celtic Sea. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00397/50829/51592.pdf |
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| Moullec, Fabien; Gascuel, Didier; Bentorcha, Karim; Guenette, Sylvie; Robert, Marianne. |
| Trophic models are key tools to go beyond the single-species approaches used in stock assessments to adopt a more holistic view and implement the Ecosystem Approach to Fisheries Management (EAFM). This study aims to: (i) analyse the trophic functioning of the Celtic Sea and the Bay of Biscay, (ii) investigate ecosystem changes over the 1980–2013 period and, (iii) explore the response to management measures at the food web scale. Ecopath models were built for each ecosystem for years 1980 and 2013, and Ecosim models were fitted to time series data of biomass and catches. EcoTroph diagnosis showed that in both ecosystems, fishing pressure focuses on high trophic levels (TLs) and, to a lesser extent, on intermediate TLs. However, the interplay between local... |
| Tipo: Text |
Palavras-chave: Ecosystem Approach to Fisheries Management (EAFM); Bay of Biscay; Celtic Sea; Ecopath with Ecosim; EcoTroph; Trophic indicators. |
| Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00377/48771/49169.pdf |
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| Trenkel, Verena; Pinnegar, J; Dawson, W; Du Buit, M; Tidd, A. |
| The spatial and temporal structure of predator-prey relationships in the Celtic Sea was investigated for 4 commercially important predator species (cod Gadus morhua, hake Merluccius merluccius, megrim Lepidorhombus whiffiagonis, and whiting Merlangius merlangus) using stomach-content and bottom-trawl survey data for the period 1982 to 1995. Blue whiting Micromesistius poutassou were consumed more often during the summer months, whereas mackerel Scomber scombrus and Trisopterus spp. (poor cod T minutus, Norway pout T esmarkii, and bib T luscus) were found more often in predator stomachs during the winter half-year. On a spatial scale, blue whiting was consumed over the shelf edge, in accordance with their higher densities in the environment, while mackerel,... |
| Tipo: Text |
Palavras-chave: Spatial distribution; Season; Celtic Sea; Preference; Stomach contents; Diet. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-3619.pdf |
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| Trenkel, Verena; Skaug, Hans. |
| We propose a random effects model for disentangling population abundance and capture efficiency effects on bottom-trawl catches. The spatial distribution of individual fish is assumed random leading to a Poisson distribution for the number of individuals in the trawl path (no schooling). Capture efficiency, i.e. the proportion of individuals in the trawl path being retained by the gear, is modelled as a random variable. We propose model extensions that include the effects of body size on haul efficiency. We applied the models to several species from the Celtic Sea groundfish community based on small-scale repetitive hauls. The resulting abundance estimates allowed us to study population abundance ratios; the estimated capture efficiencies were comparable... |
| Tipo: Text |
Palavras-chave: Trawl survey; Poisson distribution; Celtic Sea; Catchability; Abundance. |
| Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-828.pdf |
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| Pinnegar, J; Trenkel, Verena; Tidd, A; Dawson, W; Du Buit, M. |
| Feeding preferences of Celtic Sea fishes were investigated using a database of stomach content records, collected between 1977 and 1994. The diet of cod Gadus morhua, hake Merluccius merluccius, megrim Lepidorhombus whiffiagonis, whiting Merlangius merlangus and saithe Pollachius virens changed markedly as the animals grew larger, and although large predators generally chose larger bodied prey, the variability of prey sizes consumed also increased. Large predators continued to select small, low value, benthic prey (e.g. Callionymus spp. and Trisopterus spp.) which were easier to catch, rather than larger, more energy lucrative pelagic prey (e.g. mackerel Scomber scombrus), even though these pelagic prey-fishes were nearly always available and were often... |
| Tipo: Text |
Palavras-chave: Stomach contents; Preference; Diet; Celtic Sea; Availability. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-607.pdf |
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| Registros recuperados: 28 | |
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